Urban Background
Based on data from 2000 to 2002
MEDEP-BAQ is currently developing new background values based upon the most recent monitored data. Once this data has been QA'd, the new data values will be posted below.
The table that follows lists the background data values by region. The data presented here is very conservative. All of the urban values may include direct impacts from near-by sources. Many of the data values for a given region were obtained from a monitoring station outside of the region, as not all regions of the state have (or had) monitoring stations for the necessary parameters. Consequently, the listed data value for a given parameter in a particular region may not be truly representative of the background air quality for that region. In those instances where data could not be obtained from within a region, an alternative sampling site was chosen based on community size and the character of the sources impacting the alternative site being relatively similar to the region of interest.
One should recognize that more refined data analysis may have to be conducted if the data contained in this table does not permit an attainment demonstration based on screening modeling. If this proves to be the case, raw data should be obtained from MEDEP - Field Services Division for the parameter in question. These data can then be more thoroughly reviewed and a more refined background data determination made.
Map of the Air Quality Control Regions
|
Pollutant |
Southern Maine |
Central Maine |
Eastern Maine |
Northern Maine |
|
SO2 |
|
|
3-Hour |
73 (1/23/01)1 |
63 (2/3/02)2 |
63 (2/3/02)2 |
92 (3/3/97)3 |
|
24-Hour |
47 (1/22/01)1 |
29 (12/7/02)2 |
29 (12/7/02)2 |
30 (1/28/98)3 |
|
Annual |
8 (2002)1 |
9 (2002)2 |
9 (2002)2 |
8 (1997)3 |
|
PM10 |
|
|
24-Hour |
66 (1/13/01)1 |
53 (7/24/01)2 |
69 (2/19/02)4 |
73 (3/9/03)5 |
|
Annual |
24 (2002)1 |
21 (2001)2 |
17 (1997)4 |
17 (2002)5 |
|
CO |
|
|
1-Hour |
11995 (1989)1a |
11995 (1989)1a |
11995 (1989)1a |
11995 (1989)1a |
|
8-Hour |
6511 (1989)1a |
6511 (1989)1a |
6511 (1989)1a |
6511 (1989)1a |
|
NOx |
|
|
Annual |
25 (2002)1 |
25 (2002)1 |
25 (2002)1 |
25 (2002)1 |
All units are in µg/m3
KEY:
1 - Data collected at the EMPACT site, located in Portland. It is the only urban site where SO2 monitoring was conducted and is also the site with the most recent urban SO2 data in Southern Maine. NOx monitoring started at this site in 2001.
1a - Data collected at the PEOPL site, which was the predecessor to the EMPACT site and is the last site where CO monitoring was conducted.
2 - Data collected at the CKP site, located in Lewiston. This site was chosen because it is the most populated area in Central Maine and is least likely to be impacted from a single large industrial source (i.e., most representative mix of residential, commercial, and light industrial sources).
3 - Data collected at the Seventh Avenue site, located in Madawaska (monitoring data excludes Fraser Paper impacts). This site was chosen because direct impact from Fraser Paper Company would require a wind from 315 to 45 compass degrees (NW to NE) or a calm condition. Both of these conditions are less common than winds from other directions.
4 - Data collected at the KPS site, located in Bangor. This site is one of two urban sites in the Bangor area, has the longest operating history, and is considered most representative of urban air quality in Eastern Maine.
5 - Data collected at the Riverside site, located in Presque Isle. This site was chosen over the Northeastland Hotel site because it is more representative of the urban air quality in the region. The Northeastland Hotel data reflects highly localized impacts.
